The Mortal Kombat series of video games is known for its Easter eggs, such as hidden characters like Reptile and Smoke, and the “Toasty!” fighting prompt. However, there was one secret that remained locked for more than 20 years—until now. Test Your Might message board user Zpaul2Fresh8 discovered how to unlock the “EJB menus” (named for co-creator Ed Boon) that were hidden deep inside the menus of the original arcade games.

While the menus were first discovered in October when fans looked into the original game’s ROM data, no one was able to figure out how to unlock them until Zpaul2Fresh8 began tooling around with the game’s controls for a few days. He discovered a unique sequence and pattern that involved the “Block” button for Player One and Player Two for each arcade game in the original Mortal Kombat trilogy (which were released in 1992, 1993, and 1995).

Once unlocked, the menus revealed a special “hello” message to Boon's family and friends, access to each character’s endings and fatalities, an easy way to add your initials to the top of the ranking board, and the secret Galaga-like mini-game locked within Ultimate Mortal Kombat 3.

Check out the posting and video on how to unlock the menus with a long and detailed code.

[h/t Destructoid]